﻿using System;
using System.Data;
using System.Web;
using System.Web.SessionState;
using System.IO;
using System.Text;
using System.Xml;
using System.Xml.Xsl;
using System.Threading;


namespace ExportData
{

    public class DataSettoExcel
    {
         #region exportToExcel
        /// <summary>
        /// Export DataSet to Excel file
        /// </summary>
        /// <param name="source"></param>
        /// <param name="fileName"></param>
        public void ExportToExcel(DataSet source, string fileName)
        {
            var excelDoc = new StreamWriter(fileName);
            const string startExcelXML = "<xml version>\r\n<Workbook " +
                  "xmlns=\"urn:schemas-microsoft-com:office:spreadsheet\"\r\n" +
                  " xmlns:o=\"urn:schemas-microsoft-com:office:office\"\r\n " +
                  "xmlns:x=\"urn:schemas-    microsoft-com:office:" +
                  "excel\"\r\n xmlns:ss=\"urn:schemas-microsoft-com:" +
                  "office:spreadsheet\">\r\n <Styles>\r\n " +
                  "<Style ss:ID=\"Default\" ss:Name=\"Normal\">\r\n " +
                  "<Alignment ss:Vertical=\"Bottom\"/>\r\n <Borders/>" +
                  "\r\n <Font/>\r\n <Interior/>\r\n <NumberFormat/>" +
                  "\r\n <Protection/>\r\n </Style>\r\n " +
                  "<Style ss:ID=\"BoldColumn\">\r\n <Font " +
                  "x:Family=\"Swiss\" ss:Bold=\"1\"/>\r\n </Style>\r\n " +
                  "<Style     ss:ID=\"StringLiteral\">\r\n <NumberFormat" +
                  " ss:Format=\"@\"/>\r\n </Style>\r\n <Style " +
                  "ss:ID=\"Decimal\">\r\n <NumberFormat " +
                  "ss:Format=\"#,##0.###\"/>\r\n </Style>\r\n " +
                  "<Style ss:ID=\"Integer\">\r\n <NumberFormat " +
                  "ss:Format=\"0\"/>\r\n </Style>\r\n <Style " +
                  "ss:ID=\"DateLiteral\">\r\n <NumberFormat " +
                  "ss:Format=\"yyyy-mm-dd;@\"/>\r\n </Style>\r\n " +
                  "</Styles>\r\n ";
            const string endExcelXML = "</Workbook>";

            int rowCount = 0;
            int sheetCount = 1;
            excelDoc.Write(startExcelXML);
            excelDoc.Write("<Worksheet ss:Name=\"Sheet" + sheetCount + "\">");
            excelDoc.Write("<Table>");
            excelDoc.Write("<Row>");
            for (int x = 0; x < source.Tables[0].Columns.Count; x++)
            {
                excelDoc.Write("<Cell ss:StyleID=\"BoldColumn\"><Data ss:Type=\"String\">");
                excelDoc.Write(source.Tables[0].Columns[x].ColumnName);
                excelDoc.Write("</Data></Cell>");
            }
            excelDoc.Write("</Row>");
            foreach (DataRow x in source.Tables[0].Rows)
            {
                rowCount++;
                //if the number of rows is > 64000 create a new page to continue output

                if (rowCount == 64000)
                {
                    rowCount = 0;
                    sheetCount++;
                    excelDoc.Write("</Table>");
                    excelDoc.Write(" </Worksheet>");
                    excelDoc.Write("<Worksheet ss:Name=\"Sheet" + sheetCount + "\">");
                    excelDoc.Write("<Table>");
                }
                excelDoc.Write("<Row>"); //ID=" + rowCount + "

                for (int y = 0; y < source.Tables[0].Columns.Count; y++)
                {
                    Type rowType = x[y].GetType();
                    switch (rowType.ToString())
                    {
                        case "System.String":
                            string XMLstring = x[y].ToString();
                            XMLstring = XMLstring.Trim();
                            XMLstring = XMLstring.Replace("&", "&");
                            XMLstring = XMLstring.Replace(">", ">");
                            XMLstring = XMLstring.Replace("<", "<");
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                           "<Data ss:Type=\"String\">");
                            excelDoc.Write(XMLstring);
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.DateTime":
                            //Excel has a specific Date Format of YYYY-MM-DD followed by 

                            //the letter 'T' then hh:mm:sss.lll Example 2005-01-31T24:01:21.000


                            //The Following Code puts the date stored in XMLDate

                            //to the format above

                            var XMLDate = (DateTime)x[y];

                            string XMLDatetoString = XMLDate.Year +
                                                     "-" +
                                                     (XMLDate.Month < 10
                                                          ? "0" +
                                                            XMLDate.Month
                                                          : XMLDate.Month.ToString()) +
                                                     "-" +
                                                     (XMLDate.Day < 10
                                                          ? "0" +
                                                            XMLDate.Day
                                                          : XMLDate.Day.ToString()) +
                                                     "T" +
                                                     (XMLDate.Hour < 10
                                                          ? "0" +
                                                            XMLDate.Hour
                                                          : XMLDate.Hour.ToString()) +
                                                     ":" +
                                                     (XMLDate.Minute < 10
                                                          ? "0" +
                                                            XMLDate.Minute
                                                          : XMLDate.Minute.ToString()) +
                                                     ":" +
                                                     (XMLDate.Second < 10
                                                          ? "0" +
                                                            XMLDate.Second
                                                          : XMLDate.Second.ToString()) +
                                                     ".000";
                            excelDoc.Write("<Cell ss:StyleID=\"DateLiteral\">" +
                                         "<Data ss:Type=\"DateTime\">");
                            excelDoc.Write(XMLDatetoString);
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Boolean":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                        "<Data ss:Type=\"String\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Int16":
                        case "System.Int32":
                        case "System.Int64":
                        case "System.Byte":
                            excelDoc.Write("<Cell ss:StyleID=\"Integer\">" +
                                    "<Data ss:Type=\"Number\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.Decimal":
                        case "System.Double":
                            excelDoc.Write("<Cell ss:StyleID=\"Decimal\">" +
                                  "<Data ss:Type=\"Number\">");
                            excelDoc.Write(x[y].ToString());
                            excelDoc.Write("</Data></Cell>");
                            break;
                        case "System.DBNull":
                            excelDoc.Write("<Cell ss:StyleID=\"StringLiteral\">" +
                                  "<Data ss:Type=\"String\">");
                            excelDoc.Write("");
                            excelDoc.Write("</Data></Cell>");
                            break;
                        default:
                            throw (new Exception(rowType.ToString() + " not handled."));
                    }
                }
                excelDoc.Write("</Row>");
            }
            excelDoc.Write("</Table>");
            excelDoc.Write(" </Worksheet>");
            excelDoc.Write(endExcelXML);
            excelDoc.Close();
        }
        #endregion exportToExcel
    }
}
